This paper presents the preliminary results on the removing capasity of nitrogen and phosphorus in pig wastewater after anaerobic (biogas) process at pilot scale by using Eichhornia crassipes. The experimental results showed that the wastewater loading rate 50 l/m 2 .day with initial concentrations of 89.79 mgTN/l and 15.69 mgTP/l gave removal efficiency of 65.79% và 55.19%, respectively, while the wastewater loading rate 100 l/m 2 .day has removal efficiency of 39.70 % for TN and 43.29% for TP in case of input concentrations 100.38 mgTN/l and 12.52 TP/l. Thus, at the loading rate 50 l/m 2 .day, the removed quantity of TN and TP was of 2,953.64 mgTN/m 2 .day và 432.96 mgTP/m 2 .day, while at the loading rate 100 l/m 2 .day, this value was 3985.09 mgTN/m 2 .day và 541.99 mgTP/m 2 .day. The obtained results indicated that the surface flow wetland system, using Eichhornia crassipes has a rather high TN and TP removal efficiency at simple operation so that it could be feasible if applied for treating pig wastewater. However, the system should be functioned longer for taking data and for evaluating it's stability.

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Research on formulation of nanosilver-infused cream was carried out at the Institute of Environmental Technology and the effects of this cream in prevention and treatment of mastitis in dairy cows were assessed at Bavi Cattle and Forage Research Center. Cream with 0.4% carbomer was infused with silver nanoparticles for high uniformity and long-term stability. At concentrations of 50–250 ppm, nanosilver-infused cream proved to be effective against mastitis pathogens such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa. Nanosilver cream at concentrations of 150 ppm had the best effect on clinical and subclinical mastitis prevention in dairy cows. Combining nanosilver cream with ceftiofer antibiotic achieved excellent treatment rate, up to 93.33%. For prevention of dairy mastitis, silver cream can be used at a concentration of 150 ppm 15 days before calving and for the whole milking period. Using nanosilver cream in combination with antibiotics led to highly effective mastitis treatment.